I tried making a ‘Hideatsu the Ebon Ox’ deck and discovered that Shadow Waltz (which lowers the cost of all backstab minions in your action bar by 1) does not affect the trial.
For example, if I use Shadow Waltz to lower the cost of a Kaido Assassin in my action bar from
2 -> 1 and summon it, it will not fulfill the trial’s 1 drop requirement but the 2 drop’s.
This should not be the case as Ebon only states that minions have to be summoned from your action bar for it to complete so mana shifting should not be a problem so long as you summon the minion from your action bar.
Really hope they could fix this quick as Ebon is already hard to summon as is and having a bug that prevents support is a bummer